No abstract

This paper proposes an enhanced translation of SecurityProtocol Language (SPL) in high-level Petri nets in order to allow to prove automatically, using model-checking techniques, the authentication property of Needham-SchroederLowe (NSL) protocol. The proposed approach generates finite nets and goes this way beyond the limitation which was imposed by the previous semantics due to the treatment of the replication operator. In order to reach this goal, we modify the way attacks are modelled. Due to fact that the presented approach focuses on the treatment of the protocol environment, it may be successfully reused for automated verification of properties of other security protocols.

In this paper, we introduce a framework composed of a syntax and its compositional Petri net semantics, for the specification and verification of properties (like authentication) of security protocols. The protocol agents (e.g., an initiator, a responder, a server, a trusted third party,. . .) are formalized as roles, each of them having a predefined behavior depending on their global and also local knowledge (including for instance public, private and shared keys), and may interact in a potentially hostile environment. The main characteristics of our framework, is that it makes explicit, structured and formal, the usually implicit information necessary to analyse the protocol, for instance the public and private context of execution. The roles and the environment are expressed using SPL processes and compositionally translated into high-level Petri nets, while the context specifying the global and local knowledge of the participants in the protocol is used to generate the corresponding initial marking (with respect to the studied property). Finally, this representation is used to analyse the protocol properties, applying techniques of simulation and modelchecking on Petri nets. The complete approach is illustrated on the case study of the Kao-Chow authentication protocol.